When tornadoes, land falling hurricanes, and other hazards strike, National Weather Service forecasters, storm spotters, and emergency managers now have a better tool to predict, detect, and alert people to severe weather. A new radar system developed by engineers in the UMass Amherst Center for Collaborative, Adaptive Sensing of the Atmosphere (CASA) gives decision makers, for the first time, a way to see where severe weather actually forms.

CASA radars provide comprehensive coverage of the lower atmosphere so forecasters can more precisely identify storms, determine their severity, and quickly get information to those in the path of the storm. The new radar system is the result of a ten-year, multi-sector, multidisciplinary partnership among academia, industry, and government dedicated to engineering revolutionary weather-sensing networks.

The team’s cutting-edge radar system, DCAS (Distributed Collaborative Adaptive Sensing), is based on the concept of a “network of networks”—if more radars can be placed closer together, they can more accurately convey what is happening in the atmosphere where weather forms. According to Michael Zink, CASA’s deputy director for technical integration, existing long-range devices used by the National Weather Service leave a gap in detectable range where the Earth curves; the radar beam frequently overshoots critical weather by about three kilometers. Zink says this gap is the reason there is about an 80 percent false alarm rate with tornado warnings—tornados are very difficult to forecast without a fine-grain view of low-lying weather patterns.

To address the problem, the CASA team was first to develop a network of short-range radars that work collaboratively to scan the atmosphere. The resulting system nearly doubled the average tornado warning time at CASA’s Oklahoma test bed. The system’s minute-to-minute updates, versus those given every 3-5 minutes by existing technologies, also proved extremely valuable in tracking the path of a tornado. The Oklahoma test bed allowed the CASA team to test equipment in the “severe weather bulls-eye”of the nation, and DCAS consistently enabled emergency managers to get people to safety faster.

“We all get tremendously excited seeing these radars in operation and seeing them make a difference,” says Brenda Philips, CASA deputy director.

The DCAS system is especially useful with wind data; two radars working collaboratively can reconstruct the exact wind direction for a given location, whereas one radar can measure only the wind column parallel to its beam. The new radars are also designed to efficiently centralize on critical weather patterns, while existing technologies are constantly scanning all areas regardless of relevance.

The interdisciplinary center’s start-up grant of $40 million from the National Science Foundation is winding to a close, and in order to continue the center’s work, the team is launching CASA 2.0. Led by Zink and Philips, CASA 2.0 is envisioned as a mix of projects that will be funded by new grants and support from the university. CASA is pioneering how the university transitions large NSF centers into ongoing university programs.

One CASA 2.0 project is the CASA Dallas-Fort Worth Urban Demonstration Network. The CASA radars will soon be deployed in the Dallas-Fort Worth area of Texas—one of the most densely populated metropolitan areas in the country. A network of eight CASA radars is expected to be operational in 2013.

“After operating our radars in rural Oklahoma, we wanted to demonstrate the value of CASA radars in an urban environment,” explained Philips, who is leading the DFW effort. The project is also piloting a model where local, private and federal sources fund the operation and expansion of the radar network. The CASA team, which is comprised of researchers from seven universities including UMass Amherst, Colorado State, University of Oklahoma, University of Puerto-Rico, University of Delaware, University of Virginia, and McGill University, is establishing relationships with public entities and private industry to ensure the technology is carried through to fruition.

Philips is looking closely at the ideal financial formula that will enable regional deployments of the new technology. Considering both private and public entities can benefit from the radars, she and the team are closely examining how the products can be launched, operated, and maintained with pooled resources.

“It’s not that expensive for the upfront cost if you can get the right group of people together,” says Philips.

As the CASA team continues to advance these radar systems, they explore areas of national significance. If the model is successful in operating at the “x-band” frequency, a host of higher frequencies will be freed up for the improved use of 4G mobile devices. Zink and the engineering team are also conducting another CASA 2.0 research project under U.S. Ignite, a federal program that promotes research into increased bandwidth capabilities. The team is exploring algorithms to help data of all kinds travel more efficiently. Included in that pursuit is research into a special computing cloud that networks can tap into, a kind of “next generation internet” for research endeavors, which would allow radar system managers to share and sell excess Internet capabilities to others. CASA researchers are investigating ways to make such a cloud reliable and efficient enough for emergency use.

“Cloud computing is pretty nicely aligned to weather because you don’t need high computational capacities all the time,” Zink explains.

The team is additionally experimenting with ways the new radars can be synergistic with other kinds of sensors. With support from UMass alumnus Jerome Paros ’60, CASA researchers are testing how advanced ‘Paros’ barometers can work with the new CASA radars. When guided by GPS satellites, the barometers can use CASA radars to develop highly sensitive measurements of water vapor in the atmosphere—an indicator of severe weather to come. These cutting-edge capabilities appeal to a variety of organizations for different reasons. Airlines, for instance, are watching CASA’s research closely. The Dallas area is rich with such weather-sensitive industry, so the team aims to unite their products with those that could most benefit from and bring DCAS to an operational level. In addition to the improved weather detection, the new radars also offer the ability to detect low-flying aircrafts—a valuable tool for both the airlines and law enforcement agencies monitoring drug trafficking crafts that commonly fly below the radar.

“We wanted to design this network with users in mind,” says Philips.

With nationwide deployment an eventual goal, the CASA team hopes to bring the cost of the model down. A new phase tilt radar design has been stripped to essential parts and is intended to mimic the appearance of a flat-screen television.

Education is paramount to the center’s mission, and CASA offers a variety of educational opportunities for people of all ages, including the Puerto Rico test bed, which is entirely student operated and is located at the University of Puerto Rico-Mayaguez. Graduate student Jorge Trabal leads a group of his peers in a project that is catching attention in Puerto Rico and other developing areas. The students have developed low-cost, off-the-grid radar that is ideal for countries that have no radar technology.

“I think they really found the sweet spot there,” Zink says of the students’model.

The model demonstrated its life-saving capacity during the 2010 Central American and Caribbean Games (CAC) when it accurately forecasted a water spout headed directly toward the event. The unique student project is a testament to CASA’s systems approach. From the youngest student to the most experienced director, CASA aims to immerse its researchers in all aspects of the technology’s application.

Amanda Drane '12

The CASA team was first to develop a network of short-range radars that work collaboratively to scan the atmosphere. The resulting system nearly doubled the average tornado warning time at CASA’s Oklahoma test bed. View the latest coverage of CASA storm-chasers and read about the latest deployment.